While two-way converters are effective in reducing CO and HC emissions, they do not address nitrogen oxides (NOx), another major pollutant produced by internal combustion engines. For this reason, many modern vehicles use three-way catalytic converters, which can also reduce NOx. Additionally, the efficiency of two-way converters can be affected by factors such as engine temperature, fuel type, and the presence of lead in gasoline, which can poison the catalyst.
